Re: Spool Holders
I upgraded the printer and assembled the mmu2 on a large table but I can't claim that space without being forced to sleep on the couch. I humbly asked the wife to just bare with me for some test mmu prints this weekend for her even just to appease. But after that I have to figure out where I can fit everything. 1st world problems, I know.
Uh-huh, uh-huh... Sounds like someone else has seen "the scowl"!
I feel so VINDICATED!!! 😀
Sorry, but I really don't understand what you guys are arguing about. With the MMU-1, which I own, it's nothing different and it's well known for almost a year now.
Sorry, but we don't all own the MMU-1 :geek:
You should have read the articles about MMU-1, it's all the same.
Articles I read about the MMU-2 (and comparing the two) have said the MMU-2 has been completely redesigned to function entirely differently. From what I understand, the MMU-2 isn't even compatible with printers that haven't been upgraded to MK3 functionality. I only own a MK3. That was enough for me to not waste my time reading about an accessory I wasn't ever going to buy or use.
What you say may make sense to a multi-printer hobbyist who owns previous models. Perhaps not so much to first-time noobs for whom the MK3 is their first and only foray into 3D printing.
That's "MISTER Old Fart" to you!
Re: Spool Holders
What you say may make sense to a multi-printer hobbyist who owns previous models. Perhaps not so much to first-time noobs for whom the MK3 is their first and only foray into 3D printing.
At least for the moment, the MMU2 is varsity-level printing. I'd suggest making sure you really know your MK3 before attempting the MMU2.
The MMU works well, but it also greatly increases the complexity of the print, making it that much harder to figure out why something isn't working the way it should.
I suppose I could blame Prusa for not labeling it "expert users only," but I don't really expect any company to discourage paying customers that way.
Re: Spool Holders
I suppose I could blame Prusa for not labeling it "expert users only," but I don't really expect any company to discourage paying customers that way.
The fact that it comes in a kit, and with quite extensive build instructions seem to hint at "aimed for advanced users"...
It just made me wonder: most people who will get an MMU already have a running mk3. This would make it perfectly possible to have a "minimalist kit for experts" in the shop: it could include only the non-printable parts (and perhaps even forego the spool holders, adding proper remarks that positioning is important) and let the users print the printable parts. For sure that could cut the production time and lower shipping costs... and really fit with the 3D printing possibilities?
Re: Spool Holders
At least for the moment, the MMU2 is varsity-level printing. I'd suggest making sure you really know your MK3 before attempting the MMU2.
Well, I built the bloody thing from the kit, and I'm learning the rest as I go--perhaps not as quickly/easily as some (different engineering background), but it doesn't intimidate me as much as it did before assembling it.
The MMU works well, but it also greatly increases the complexity of the print, making it that much harder to figure out why something isn't working the way it should.
I suppose I could blame Prusa for not labeling it "expert users only," but I don't really expect any company to discourage paying customers that way.
Doesn't exactly jibe with "you can start printing right away without any hassle" and "the whole process is as trouble-free as possible", does it? 😉 😆
There were a lot of reasons I settled on this particular printer, the hyped MMU-2 being high on the list. Among others (in no particular order):
Probably a few others that don't come to mind as I type this...
I never expected plug & play, however I wasn't expecting a major ordeal at nearly every step either--not the way it's being marketed and reviewed. The design & rush-to-market issues with the MMU-2 are kind of throwing me--seemingly not consistent with what I've read/been led to believe. They're doing some good things, but IMO some should--and could--be done much better.
That's "MISTER Old Fart" to you!
Re: Spool Holders
Doesn't exactly jibe with "you can start printing right away without any hassle" and "the whole process is as trouble-free as possible", does it? 😉 😆
I think "the whole process is as trouble-free as possible" is an accurate statement.
You will note that they don't claim "the while process is as trouble-free as you think it will be." That would clearly be inaccurate for pretty much everyone I know including myself.
Re: Spool Holders
I definitely share the surprise at being required to dedicate an additional '40cm + spools' of table depth to make the MMU2 setup work in the recommended way. Maybe my fault for not researching it more before buying, but I simply don't have that amount of extra space. I'm currently testing a condensed spool setup that I posted here:
Re: Spool Holders
Give it a month or two and I expect there will be several overhead mounted spool designs.
Re: Spool Holders
Now that the shipping list is out, I am just glad I have some wait and see time to see how this pans out. I figure I will make a decision whether to cancel or not by mid-October. The posts so far seem to lean toward issues (barely out of beta) versus look at my awesome prints.
Re: Spool Holders
Where is the shipping list? ❓
Re: Spool Holders
Re: Spool Holders
Now that the shipping list is out, I am just glad I have some wait and see time to see how this pans out. I figure I will make a decision whether to cancel or not by mid-October. The posts so far seem to lean toward issues (barely out of beta) versus look at my awesome prints.
Still doing test and calibration prints, which means a lot of turtles. Here's some of my awesome prints:
The sheep in front was my first "Hello World" print. The turtle in the back shows a particularly severe case of filament not loading properly. Those multicolor cubes and towers are for calibrating the purge volumes.
I'm actually just starting on my first "real" print now, a trophy I'm designing for an upcoming event.
As frustrating as some of the early failures have been, I think so far the MMU is outperforming my Palette+. I also really like the convenience of keeping a bunch of filaments loaded and selecting the one I want for single-color prints.
Re: Spool Holders
The sheep in front was my first "Hello World" print. The turtle in the back shows a particularly severe case of filament not loading properly. Those multicolor cubes and towers are for calibrating the purge volumes.
Could you share a link or STL for those purge calibration cubes? Those look really handy. Thx.
Re: Spool Holders
Back to spool holders.
At last, I managed to find time to print some modified filament feeds for the holders, and tested with a 2C print.
The filament feed tubes have been about halved and the printer is back to (almost) how it was with MMU1.
Seems to work fine so far, but I have some other things to try (when I get time).
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Spool Holders
Back to spool holders.
At last, I managed to find time to print some modified filament feeds for the holders, and tested with a 2C print.
The filament feed tubes have been about halved and the printer is back to (almost) how it was with MMU1.
Peter, it looks like you have abandoned the "brake" mechanism... what is keeping all the unloaded slack in the filament from making your spools unwind and get all messy? I tried a couple prints without the brakes, and it turned my spools into a tangled mess.
Re: Spool Holders
Peter, it looks like you have abandoned the "brake" mechanism... what is keeping all the unloaded slack in the filament from making your spools unwind and get all messy? I tried a couple prints without the brakes, and it turned my spools into a tangled mess.
The feeds on the spool holders are modified; they provide sufficient friction to prevent backfeed onto the spools and because the PTFE is not locked into the feeds, the loops just form.
Furthermore, there is significantly less friction when unloading, so I have been able to reduce the Bondtech tension.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Spool Holders
The sheep in front was my first "Hello World" print. The turtle in the back shows a particularly severe case of filament not loading properly. Those multicolor cubes and towers are for calibrating the purge volumes.
Could you share a link or STL for those purge calibration cubes? Those look really handy. Thx.
Found them: https://www.thingiverse.com/thing:3102486
Re: Spool Holders
Peter, it looks like you have abandoned the "brake" mechanism... what is keeping all the unloaded slack in the filament from making your spools unwind and get all messy? I tried a couple prints without the brakes, and it turned my spools into a tangled mess.
The feeds on the spool holders are modified; they provide sufficient friction to prevent backfeed onto the spools and because the PTFE is not locked into the feeds, the loops just form.
Furthermore, there is significantly less friction when unloading, so I have been able to reduce the Bondtech tension.
Peter
Cool, thanks for posting the STL. Will check it out.
Re: Spool Holders
One thing on the current spool holders: the friction is quite high. I was printing (without MMU2 engaged) with a heavy Ninjatek Cheetah spool and I had to tug quite hard to get it to spin.
The bearings spin pretty freely, but the spinning rod is so narrow every 2.5 cm of filament pulled rotates the bearings a full 360 degrees. I've had better luck with the inside of the bearing fixed and the outside (22mm D) bearing the sides of the filament roll. Much less angular movement for a given amount of filament.
I'm planning to redesign the base a bit (same brake mechanism for now) using 1" rollers (1" sch 40 PVC mounted on the outside of the bearings with some printed shims, inside of the bearings stationary). With that, there should be less bearing friction (8cm of filament pull to rotate the bearings 360). I'll do a 1:1 comparison with a strain gauge and see how it goes.
It'll be fun to try, if nothing else. There is enough friction added in the MMU2 system that anyplace I can reduce it I'm going to (braking mechanism, boring out holes that do not need to be tight, shorter Bowden, etc.)
Re: Spool Holders
One thing on the current spool holders: the friction is quite high. I was printing (without MMU2 engaged) with a heavy Ninjatek Cheetah spool and I had to tug quite hard to get it to spin.
The bearings spin pretty freely, but the spinning rod is so narrow every 2.5 cm of filament pulled rotates the bearings a full 360 degrees. I've had better luck with the inside of the bearing fixed and the outside (22mm D) bearing the sides of the filament roll. Much less angular movement for a given amount of filament.
I'm planning to redesign the base a bit (same brake mechanism for now) using 1" rollers (1" sch 40 PVC mounted on the outside of the bearings with some printed shims, inside of the bearings stationary). With that, there should be less bearing friction (8cm of filament pull to rotate the bearings 360). I'll do a 1:1 comparison with a strain gauge and see how it goes.
It'll be fun to try, if nothing else. There is enough friction added in the MMU2 system that anyplace I can reduce it I'm going to (braking mechanism, boring out holes that do not need to be tight, shorter Bowden, etc.)
Success! I've designed new rollers for the spool holders. It made a much bigger reduction in friction than I expected. Check it out in the mod forum, with video. Full Post.
Re: Spool Holders
Here is my take on spool holding - I built a custom shelf with rods that sits on the backside of the printer to hold all my filament, and created my own filament guides that use the original lever-a and lever-b from the spool holders in the kit. I have not actually received my MMU 2.0 kit yet, but I just got the shipping notification and am all ready! 🙂
https://www.thingiverse.com/thing:3115033
